A classical mechanics problem by Aditya Kumar

The moment of inertia of a single particle about a given axis is defined as the product of it's mass and the square of the perpendicular distance from the axis. Going further, the M.I of a rigid body is the sum of the M.I's of all the particles that constitute it.

What is the moment of inertia of a cube-shaped shell (walls are of zero thickness) with mass 16 units and side of length 6 units about an axis passing through the centres of any two faces that are opposite to each other ?